E. Cois Experiment

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Goals
E. coli is a type of bacteria that sense and swim towards sugar, amino acids, pyrimidines and electron acceptors. Thus, the goal of this experiment was to determine whether E. coli has a direct motion or random motion when a chemoattractant (glucose) was present. This was done by observing the velocity before and after the chemoattractant and by making Log-Log Plot.

Theoretical
Chemotaxis refers to the ability of organisms to move in response to the presence of a chemical. The movement of organisms could be either attractant in the same direction as chemoattractants , or it can repel the chemoattractant. Direct motion is defined when an organism move with regard to a reference point in a followed pathway. However, bacteria might also move randomly as a result of their collision with other fast moving particles in various environments.
When there is a gradient present, E. coli moves to the chemical emitted from the chemoattractant. The attracted chemical binds to the chemoreceptors known as methyl-accepting chemotaxis proteins in the cell membrane of E. coli. E. coli
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coli move faster toward a preferred environment which contains glucose. The results showed that when the glucose was present, E coli had a velocity of 7.98m/s. Whereas, the velocity was 5.59m/s when there was not glucose. The values showed that the glucose influenced the velocity of E. coli by increasing it. Figure 1 also showed that the presence of a chemoattractant affected the velocity of E. coli. The figure 2 determined that E. coli has both random and directed motion. This was concluded based on the different slopes observed in the graphs. When the slope was below 1, it was determined to have confined, trapped and caged motion. These happened at points ~ 0.33 to ~1.0 log(sec), and from ~ 1.2 to ~1.5 log(sec). When the slope was between 1 and 2, it was determined to have random and directed motion. These happened between ~1.0 and ~1.2

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